The present invention relates to a hydraulic pump driven by an internal combustion engine. More particularly, the present invention relates to a hydraulic unit or system including a hydraulic pump driven by a camshaft of an internal combustion engine for providing pressure fluid to engine-compartment consumers in automotive vehicles.
A pump of this type is disclosed in German Patent Publication number DE-OS 40 33 105. According to the system disclosed by this reference an internally pressurized radial piston pump is flanged to the engine housing and has an air-flow sensor flap between the pump housing and the engine housing. The phrase "internally pressurized" means that the pressurization of the fluid occurs radially inward relative to the piston. The airflow sensor flap is provided with a central opening, through which a clutch extends that interconnects the pump motor and the drive shaft of the engine.
Undesirably, this known system requires a large number of component parts and the pump of this system necessitates a relatively large mounting space. In particular, in up-to-date automotive vehicles, it is desirable to reduce the dimensions of the units which are accommodated in the engine compartment to the greatest possible extent.